KR20100026647A - Zigbee system and formation method of zigbee network - Google Patents

Abstract

PURPOSE: A Zigbee system and a formation method of a Zigbee network are provided to reduce data transmission amount and signal processing amount when multiple Zigbee devices transceive scan request messages or scan response messages. CONSTITUTION: A predetermined Zigbee device broadcasts a scan request message. If a scan response message is received, the Zigbee device selects a router or a coordinator of which reception signal strength is decided to be the strongest in order to configure a Zigbee network. An RFD(Reduced Function Device)(E) receives the scan request message in a broadcast transmission distance. If a scan response message is received, the RFD selects a router or a coordinator of which reception signal strength is decided to be the strongest in order to configure a Zigbee network.

Description

Zigbee system and formation method of zigbee network

Embodiments relate to a Zigbee system and a Zigbee network configuration method.

Ubiquitous network technologies include ZigBee, Bluetooth, and Radio Frequency IDentification (RFID). Among them, interest in Zigbee technology, which is one of the IEEE 802.15.4 standards supporting near field communication, have.

ZigBee technology has the advantage of being able to transmit data at speeds of about 250 Kbps over a communication distance of 10m up to 1km, connecting various thousands of devices by forming various network topologies, and having low power consumption.

The Zigbee network is composed of a Zigbee device such as a coordinator for managing the network, a Full Function Device (FFD) that performs the routing function of the network, and a Reduced Function Device (RFD) that operates as an end device.

In general, the method of configuring a Zigbee network is as follows.

First, the first RFD transmits a scan request message in a broadcast manner. In this case, since the scan request message does not have a destination address, routers around the first RFD may receive all of the scan request messages.

Second, the routers receiving the scan request message configure the network information including the channel, the personal area network identification (PAN ID), and the network ID as a scan response message to the first RFD.

Third, the first RFD receives a plurality of the scan response messages and selects a router that transmits the scan response message having the greatest strength of the received signal. When the router is selected, the first RFD joins the routing path of the selected router by using corresponding network information.

Fourth, second RFD, third RFD,... Then, the n-th RFD processes the first to third processes, respectively, to select a router located closest to each other and form a Zigbee network.

As such, it is important to configure the Zigbee network to find the router with the nearest RFD, where each RFD broadcasts a scan request message, and the routers repeat the same scan response message for each scan request message, i.e. You have to send as many numbers.

Therefore, since the router is subjected to a load for signal processing, network traffic increases in this process, and obstacles such as data collisions occur, it is difficult to construct a Zigbee network.

According to an embodiment of the present invention, when a plurality of ZigBee devices transmit and receive a scan request message and a scan response message to configure a ZigBee network, data transmission and signal throughput may be reduced to minimize the probability of scan failure and to efficiently configure the ZigBee network. It provides a Zigbee system and a Zigbee network configuration method.

The Zigbee system according to the embodiment relates to a Zigbee system including a coordinator, a router, and a Zigbee device including an RFD, wherein the router or the coordinator receives a scan request message and broadcasts a scan response message; A predetermined ZigBee device configured to broadcast a scan request message and enter a response standby mode, and select the router or the coordinator which is determined to have the greatest strength of the received signal when the scan response message is received to form a Zigbee network; And form the group by receiving the scan request message within a broadcast transmission distance, enter a response standby mode, and when the scan response message is received, select the router or the coordinator determined that the strength of the received signal is the highest. It contains the RFDs that make up the Zigbee Network.

A method for configuring a Zigbee network according to an embodiment is related to a method for configuring a ZigBee network of a ZigBee device including a coordinator, a router, and an RFD; Entering the response waiting mode by forming a group of the RFDs receiving the scan request message within a broadcast transmission distance; The router or the coordinator receiving the scan request message to broadcast a scan response message; Detecting the strength of a received signal by the predetermined ZigBee device and the RFD that have received the scan response message, and selecting the router or the coordinator which has transmitted the signal determined to have the greatest signal strength; And connecting the predetermined ZigBee device and the RFD to the selected router or coordinator to configure a ZigBee network.

According to the embodiment, the following effects are obtained.

First, in order to configure a ZigBee network, when a plurality of ZigBee devices transmit and receive a scan request message and a scan response message, it is not necessary to repeatedly transmit and receive each message and may eliminate duplicate messages.

Second, therefore, the Zigbee network can be configured by minimizing the load, network traffic, and data collisions on each Zigbee device, and the efficiency of the Zigbee network can be maximized.

Third, since the transmission / reception amount of the scan request message and the scan response message can be greatly reduced, the Zigbee device can operate stably for a long time by minimizing power consumption.

With reference to the accompanying drawings, it will be described in detail a configuration method of a Zigbee system and a Zigbee network according to the embodiment.

Hereinafter, in describing the embodiments, detailed descriptions of related well-known functions or configurations are deemed to unnecessarily obscure the subject matter of the present invention, and thus only the essential components directly related to the technical spirit of the present invention will be referred to. .

FIG. 1 illustrates a state in which components of a Zigbee system maintain a scan standby mode, and FIG. 2 illustrates a state in which some components of a Zigbee system enter a response standby mode. This is a drawing.

1 and 2, the Zigbee system according to the embodiment is composed of a plurality of Zigbee devices, the Zigbee device is a reduced function device (RFD), a router (R) operated as an end device (E) A router, or a coordinator. 1 and 2, only RFD (E) and router (R) are shown for convenience of description.

3 is a diagram illustrating a protocol stack structure illustrating an area of data processed in a Zigbee system according to an embodiment.

According to FIG. 3, the Zigbee protocol stack is largely classified into a physical (HY) layer (SHY) (S5), a media access controller (MAC) layer (S4), a network (network / security) layer (S3), and an application framework. Layer S2 and application / profiles S1, wherein the PHY layer S5 and the MAC layer S4 correspond to an IEEE standard area, and the network layer S3. The framework layer S2 corresponds to a prescribed area of Zigbee Alliance, and the application layer S1 corresponds to an application area related to database management and control information generation.

The ZigBee device may function as an RFD, a Full Function Device (FFD), or a coordinator according to a type of a loaded program, that is, a program that processes data of the network layer S3 and the framework layer S2.

The FFD performs functions such as network initialization, node management, and node information storage, and can communicate with all other FFDs or RFDs. In addition, the FFD that allows the remaining Zigbee devices to configure any one of the three nodes described above is called a personal area network (PAN) coordinator.

The coordinator configures a PAN identified by a channel and a PAN ID, and assigns a network address to a router or an RFD.

The RFD is a Zigbee device that does not perform a coordinator function and a routing function and operates as an end device. The RFD may be a coordinator and may communicate with a router or coordinator. That is, the RFD may participate in a PAN configured with the same channel and PAN ID.

The FFD, which is controlled by the coordinator and processes a routing path and delivers data to the RFD, is called a router. The router participates in a PAN composed of the same channel and PAN ID, and assigns a network address to another router or RFD that has not yet participated in the PAN to participate in the PAN.

FIG. 4 is a block diagram schematically illustrating components of a Zigbee device 100 constituting a Zigbee system according to an embodiment, and FIG. 5 schematically illustrates a form of a data packet processed in a Zigbee system according to an embodiment. Data structure diagram.

As described above, the Zigbee apparatus 100 illustrated in FIG. 4 may be operated as an RFD, a router, or a coordinator according to the type of a loaded program. The control unit 110, the storage unit 120, and the pulse processor 130 may operate. , RF receiver 140, RF transmitter 150, power control circuit 160, phase synchronization circuit 170, and antenna 180.

In addition, the control unit 110 includes a mode control unit 112, a multiple transmission unit 114, a network configuration unit 116, a period calculation unit 118, the RF receiver 140 is a signal strength detection Section 142.

Referring to FIG. 5, the data packet generated by the controller 110 may include a preamble (D1), a start of packet delimiter (SPD), a PHY header (D3), a PHY service data unit (PSD), and the like. The preamble (or “beacon” can be used) D1 means a series of pulse signals that can be interpreted between ZigBee devices to synchronize transmission timing.

The SPD D2 informs the counterpart ZigBee device that the actual packet data has begun and indicates an analysis point of the PHY header, and the PHY header D3 contains analysis information of the PHY layer (physical layer) S5. The PSDU D4 is a section in which application data is loaded along with routing information.

The scan request message, the scan response message, etc. according to the embodiment may be configured and transmitted in the form of a data packet shown in FIG. 5.

The controller 110 configures a network topology by performing a function of a software Mac layer, a function of a network layer S3, a function of a framework layer S2 (see FIG. 2), and an application layer S1. Manage your database and configure the Zigbee Network by performing its functions.

For detailed operations of the mode control unit 112, the multiplexing unit 114, the network configuration unit 116, and the periodic operation unit 118 constituting the control unit 110, a Zigbee network is described with reference to FIG. 6. It will be described together with the configuration method.

The RF receiver 140, the RF transmitter 150, the phase synchronization circuit 170, and the power control circuit 160 are components that process operations corresponding to the PHY layer S5. Determine the topology.

The RF receiver 140 and the RF transmitter 150 connected to the antenna 180 use a Direct Sequence Spread Spectrum (DSSS), and in the 2.4 GHz band, 32-PN code length O-QPSK (Offset-Quadrature Phase) -Shift Keying) The RF and digital signals are converted and processed using the modulation and demodulation method.

In addition, the phase synchronization circuit 170 provides an oscillation frequency signal to the RF receiver 140 and the RF transmitter 150, and the power control circuit 160 determines the strength of the received signal to adjust the amount of transmission power. do.

The MAC (Media Access Controller) processor 130 analyzes the transmitted data frame structure to approve the frame, detects an error (detects it via CRC or Checksum), and determines whether to retransmit the packet. Handle the routing.

Hereinafter, a method of configuring a Zigbee network according to an embodiment will be described in detail with reference to FIG. 6.

6 is a flowchart illustrating a method of configuring a Zigbee network according to an embodiment.

First, the ZigBee devices illustrated in FIG. 1 may request a ZigBee network configuration by transmitting a scan request message by broadcasting.

The Zigbee device capable of requesting the Zigbee network configuration may be a coordinator, a router, or an RFD.

For convenience of description in the embodiment, it is assumed that the Zigbee device requesting the initial network configuration is an RFD.

In addition, since the operation of the router and the coordinator is similar when adding a reference description, only the router will be described by way of example. In this case, the operation of the router may be applied to the coordinator.

When the Zigbee device requesting the network configuration is the RFD (E) ("RFD" in S100), the RFDs (E) are different from the start time of entering the scan standby mode and maintaining the scan standby mode, respectively. The scan standby mode is maintained for a random period (S100 and S105).

When the random period is terminated (YES in S110), the mode control unit (FIG. 4; 112) of any of the RFDs (E) enters a scan mode, and the multi-transmitter 114 sends a scan request message. Broadcast (S115).

The scan request message includes a content of requesting a PAN ID from the router R or the coordinator.

Meanwhile, when the Zigbee device requesting the network configuration is a router (“router” in S100), the router R may immediately broadcast a scan request message without going through steps S105 to S110 (S115).

Thereafter, the RFD (E) that broadcasts the scan request message enters the response waiting mode (S120).

At this time, only the router (R) existing within the range of the broadcast, other RFD (E) can receive the scan request message, the RFD (E) transmitting the scan request message, the other RFD (in the broadcast range) E) are grouped together (G1 in FIG. 2) and are considered as having sent the original scan request message.

The other RFDs (E) that have received the scan request message enter the response standby mode from the scan standby mode in the same manner as the RFD (E) that has transmitted the scan request message (S125).

That is, a plurality of RFDs (E) may start scanning the neighbor nodes at random rather than being ordered, and when one RFD (E) starts scanning, the other RFDs (E) wait for response in the scan standby mode. To enter the mode.

At this time, another RFD (E) that exists outside the broadcast range is regarded as a group (G2 of FIG. 2) that did not transmit the original scan request message, and maintains a scan standby mode.

Each of the RFDs (E) calculates the period of the response standby mode, and scans again when the period of the response standby mode is terminated without receiving a scan response message from the router R (YES in S130). The mobile station enters the standby mode and reapplies each random period (S105).

Further, even if the response standby mode of the RFDs (E) is not terminated, if all of the routers (R) are out of the broadcast transmission range, no router (R) can transmit a scan response message (S135 " no").

In this case, the RFDs (E) enter the scan standby mode and apply a random period again (S105).

That is, when the response waiting mode of the RFD (E) is terminated or the router (R) spaced apart from each other cannot transmit the scan response message before the router (R) transmits a scan response message, another RFD (E) ) Can be transferred randomly.

On the other hand, if the router (R) receiving the scan request message broadcasts the scan response message (YES in S135) in a state in which the cycle of the response waiting mode is not finished (NO in S130), the response wait waits. All of the RFDs (E) in the mode may receive a scan response message and configure a Zigbee network (S140).

At this time, all of the routers (R) receiving the scan request message broadcast a scan response message.

The RFDs (E) receive scan response messages from a plurality of adjacent routers (R), and the signal strength detecting unit (FIG. 4; 142) of the RFD (E) detects the strength of a received signal and detects information. Create

For example, the signal strength detecting unit 142 may be provided as a log amplifier, and outputs an intermediate frequency signal in an analog state as a DC voltage signal and converts the power level into a state capable of detecting a power level.

In this case, the signal strength detecting unit 142 may extend the signal sensitivity range of the power level that can be received by outputting the intermediate frequency signal as a DC voltage signal proportional to a direct decibel value.

When the sensing information is transmitted from the signal strength detecting unit 142, the network configuring unit 116 converts the detected information into a comparable digital signal and records the same in the storage unit 120.

The network configuration unit 116 compares the sensing information recorded for each router R, selects a router determined to have the largest signal strength, and analyzes the scan response message of the selected router R to determine network information, such as Extract channel, PAN ID and device identification information.

The network configuration unit 116 records the network information and the detection information in a scan table of the storage unit 120 and sets the routing information as its routing information.

Then, when the RFD (E) is connected to the router (R) using the set routing information, the router (R) recognizes the RFD (E) located in its periphery and tells the RFD (E) a network Give an ID.

Accordingly, a plurality of RFDs E forming a group G1 within the broadcast range of the original scan request message may simultaneously configure a Zigbee network through a single scan request and a scan response process.

Subsequently, other RFDs E that form the group G2 outside the broadcast range of the original scan request message may configure a separate Zigbee network by performing the process of steps S100 to S140.

The period calculating unit 118 of FIG. 4 calculates a random period of the scan standby mode and a period of the response standby mode, and the mode controller 112 transmits and receives the calculated period, the scan request message, and the scan response message. Handle each mode switch.

The present invention has been described above with reference to the preferred embodiments, which are merely examples and are not intended to limit the present invention, and those skilled in the art to which the present invention pertains do not depart from the essential characteristics of the present invention. It will be appreciated that various modifications and applications are not possible that are not illustrated above. For example, each component specifically shown in the embodiment of the present invention can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

1 is a view schematically illustrating a state in which components of a Zigbee system maintain a scan standby mode according to an embodiment.

2 is a view schematically illustrating a state in which some components of the Zigbee system enter the response waiting mode.

3 is an exemplary protocol stack structure diagram illustrating an area of data processed in a Zigbee system according to an embodiment.

4 is a block diagram schematically illustrating components of a ZigBee device constituting a ZigBee system according to an embodiment.

5 is a data structure diagram schematically showing the form of data packets processed in the Zigbee system according to the embodiment.

6 is a flowchart illustrating a method of configuring a Zigbee network according to an embodiment.

Claims (22)

In a Zigbee network configuration method of a Zigbee device including a coordinator, a router, an RFD, The predetermined Zigbee device broadcasting a scan request message and entering a response waiting mode; Entering the response waiting mode by forming a group of the RFDs receiving the scan request message within a broadcast transmission distance; The router or the coordinator receiving the scan request message to broadcast a scan response message; Detecting the strength of a received signal by the predetermined ZigBee device and the RFD that have received the scan response message, and selecting the router or the coordinator which has transmitted the signal determined to have the greatest signal strength; And And configuring the Zigbee network by connecting the predetermined Zigbee device and the RFD to the selected router or coordinator. The method of claim 1, wherein the scan request message is A method for configuring a Zigbee network, comprising: requesting a PAN ID. The method of claim 1, wherein the scan response message And a channel, a PAN ID, and device identification information of the router or the coordinator. The device of claim 1, wherein the predetermined Zigbee device is And the coordinator, the router, or the RFD. The method of claim 1, wherein the predetermined Zigbee device enters the response standby mode. Maintaining the scan standby mode state for a random period by varying a mode start time and a mode hold time by the RFD; And when the random period ends when the predetermined ZigBee device is an RFD, the RFD enters a scan mode from the scan standby mode and broadcasts the scan request message. 6. The method of claim 5, wherein the RFD receiving the scan request message forms a group to enter a response standby mode. And the RFD of another group which has not received the scan request message maintains the scan standby mode. The method of claim 5, wherein the router or the coordinator broadcasts a scan response message. Calculating a period of the response standby mode by the predetermined ZigBee device and the grouped RFD; And when the period of the response standby mode ends when the scan response message is not received, returning the predetermined ZigBee device and the grouped RFD to maintain the scan standby mode state. Configuration method. The method of claim 5, wherein the router or the coordinator broadcasts a scan response message. When the router or the coordinator is located outside the broadcast transmission distance of the scan request message and fails to transmit the scan response message, Returning the predetermined ZigBee device and the grouped RFDs to maintain the scan standby mode state. The method of claim 1, wherein the predetermined ZigBee device and the RFD select the router or the coordinator. Extracting, by the predetermined ZigBee device and the RFD, channel response information of the selected router or coordinator to extract one or more network information among channels, PAN IDs, and device identification information; And And recording, by the predetermined ZigBee device and the RFD, the network information and detection information of a received signal strength in a scan table. The method of claim 1, wherein configuring the Zigbee network Connecting the predetermined ZigBee device and the RFD to the selected router or coordinator; The connected router or the coordinator assigning a network ID to the predetermined Zigbee device and the RFD; And And configuring, by the predetermined ZigBee device and the RFD, a ZigBee network with the router or coordinator and performing data communication. The method of claim 1, Configuring the ZigBee network by the ZigBee devices failing to form the group outside the broadcast transmission distance, broadcasting the scan request message and entering a response standby mode, and configuring the ZigBee network. Way. In a Zigbee system consisting of a coordinator, a router, a Zigbee device including an RFD, The router or the coordinator for receiving a scan request message and broadcasting a scan response message; A predetermined ZigBee device configured to broadcast a scan request message and enter a response standby mode, and select the router or the coordinator which is determined to have the greatest strength of the received signal when the scan response message is received to form a Zigbee network; And The scan request message is received within a broadcast transmission distance to form a group, and a response wait mode is entered. When the scan response message is received, the Zigbee is selected by selecting the router or the coordinator having the greatest strength of the received signal. A Zigbee system that includes the RFDs that make up the network. The method of claim 12, wherein the scan request message is Zigbee system comprising a request for a PAN ID. The method of claim 12, wherein the scan response message ZigBee system comprising the channel, PAN ID, device identification information of the router or the coordinator. The device of claim 12, wherein the predetermined Zigbee device is Zigbee system, characterized in that any one of the coordinator, the router, the RFD. The method of claim 12, wherein the RFD is Calculate a random period by varying a mode start time and a mode holding time, maintain a scan standby mode state during the random period, and when the random period ends, enter the scan mode from the scan standby mode and scan the message. Zigbee system, characterized in that for broadcasting. 17. The RFD of claim 16, wherein the RFD of another group that has not received the scan request message is ZigBee system, characterized in that to maintain the scan standby mode. The method of claim 16, wherein the RFD is ZigBee system characterized in that to calculate the period of the response standby mode, and when the period of the response standby mode is terminated in the state that the scan response message is not received, the random period is recalculated to enter the scan standby mode . The method of claim 16, wherein the RFD is And the router or the coordinator is located outside the broadcast transmission distance of the scan request message and fails to transmit the scan response message, and enters the scan standby mode by recalculating the random period. 13. The method of claim 12, wherein the ZigBee device of at least one of the predetermined ZigBee device and the RFD ZigBee characterized in that the channel response information of the selected router or coordinator is analyzed to extract one or more network information among a channel, a PAN ID, and device identification information, and the detected information of the network information and received signal strength is recorded in a scan table. system. The method of claim 12, When one or more ZigBee devices of the predetermined ZigBee device and the RFD connect to the selected router or coordinator, And the connected router or the coordinator configures the Zigbee network by assigning a network ID to one or more ZigBee devices of the predetermined ZigBee device and the RFD. The method of claim 16, The RF receiver of the Zigbee device includes a signal strength detector for detecting the signal strength of the scan response message to generate the detection information, The control unit of the Zigbee device converts the detected information into a digital signal, compares the detected information, selects the router or coordinator determined to have the greatest strength of the received signal, and routes network information of the selected router or coordinator to routing information. Network configuration unit to process; A periodic calculator configured to calculate a random period of the scan standby mode and a period of the response standby mode; A mode controller configured to handle mode switching according to transmission and reception of the calculated period, the scan request message, and the scan response message; And a multiple transmitter configured to broadcast the scan request message or the scan response message.

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